Research On Digital Control Technology For Single-Phase Active Power Factor Correction

In recent years, extensive use of power electronic devices has resulted in serious harmonic pollution in the grid. In order to limit the harmonic pollution of power electronic devices, many contries have established the harmonic standards. Active Power Factor Correction (APFC) technology is an important measure to limit the harmonic current of power electronic devices. It has become an important research direction of power electronics. With the development of integrated circuit and digital control technology, power factor correction based on digital control has become a hotspot of research in power electronics field.Now, the digital control algorithm of PFC is mostly based on traditional analog control strategy. Most of the analog control algorithms are very complex, as a result the traditional digital control algorithms have a lot of calculation, and have a high demand for digital control chip, the advantages of digital control can not be full play. In order to overcome this shortcoming of digital control PFC, the thesis introduces a new predictive control algorithm of PFC, and get a good correction results in Boost PFC circuit based on digital control.Firstly, this thesis introduces the significance,concept and development of power factor correction, and summarizes the advantages of power factor correction with digital control. Secondly, this thesis describes the basic topology, control mode and the basic control methods of active power factor correction, and then analyses a new predictive control algorithm of PFC. Thirdly, the small-signal model of single-phase PFC based on new predictive control algorithm is built and PI controller is designed. The effectiveness of the PI controller and the characteristics of the new control algorithm is researched by simulation in Malab. Finally, on the basis of theoretical analysis, the experimental prototype is made, the software of the control system is writen and the experimental study of the new predictive control algorithm is done.Simulation and experimental results show that the new predictive control algorithm of PFC has a good power factor correction effect and stronger anti-interference. It’s more simple and practical compared to traditional control algorithm.